how do you drain a coolant expansion tank

How do you drain a coolant expansion tank?

1. Prepare the vehicle.
2. Spray WD-40 on any rusted bolts.
3. Locate the coolant reservoir.
4. Remove the bolts securing the reservoir to the engine compartment.
5. Remove the two top hoses.

Full Answer

How do you put coolant in the expansion tank?

Pour the coolant mixture into the expansion tank until it reaches 1 in. (25 mm) above the top level line. Replace the cap. Remove the radiator cap and fill the main system with coolant through the radiator opening until it will take no more and there is a trickle of coolant from the heater bleed screw.

How do I drain the water from my expansion tank?

Connect the garden hose to the drain valve to drain the water into the drain outside. You can also place a large bucket directly under the drain valve to collect the water as it drains out. Open the drain valve on the expansion tank.

How do I drain the coolant from the system?

The system is supposed to be maintenance-free, and is drained only when a hose or the coolant is due for replacement. When draining and refilling the system, if the coolant is to be reused, place clean containers beneath the drain points. Note that the coolant is poisonous. Do not use containers which will be used in or near the kitchen.

How does the coolant transfer from the tank to the system?

The coolant is transferred back and forth between the tank and cooling system depending on the pressure. In order for this cooling system to work effectively, it needs to be sealed.

What is draining water out of a waterlogged expansion tank?

Draining water out of a waterlogged expansion tank is a common heating boiler service procedure used to replace a lost air charge. If this step is not taken when needed the waterlogged compression / expansion tank will cause boiler leaks and improper, even unsafe boiler operation.

What valve allows water to enter the expansion tank?

The water valve that permits the heating system or boiler water to enter the expansion tank is closed before opening the tank drain. Then the expansion tank drain is opened; most of these old tanks use a special expansion tank drain valve that lets air into the tank as water drains out.

What happens if your Amtrol expansion tank is waterlogged?

If your Amtrol expansion tank is waterlogged there is a problem to correct. It might be a slow loss of the tank's air charge over several years, fixed simply by adding air. IF the tank has a pinhole leak or a if your bladder-type expansion tank has suffered ruptured bladder, the tank probably needs replacement.

Do boiler expansion tanks have a drain valve?

Many expansion tanks use a special drain valve that permits air to flow into the tank as water is drained out. But some don't. Here we give a step by step procdure for draining a traditional (bladderless) boiler expansion tank in order to then get the proper air charge into the tank.

Does the hose work on an expansion tank?

But the hose only works if a special air-admittance valve is installed on your expansion tank. If your expansion tank just has a regular boiler drain valve installed, the hose thing will be very difficult to work - in that case plan some trips with a bucket held under the opened tank drain valve instead.

Is the expansion tank hot?

Watch out, the expansion tank water could be hot, and is usually a bit smelly and dirty. Let all of the water out of the expansion tank. You could get away with a bit less than all, but all is good. This lets us start with an expansion tank full of air.

Does an expansion tank drain valve have an air inlet?

Some expansion tank drain valves include an extra feature, an air inlet that allows air to enter the expansion tank through an air inlet on the drain valve at the same time that water is draining out of the expansion tank . Watch out, the expansion tank water could be hot, and is usually a bit smelly and dirty.

How to empty coolant system?

To empty the system, let the engine cool, take the cap off the expansion tank, put the heater control inside the car on 'hot', and open the drain tap or remove the bottom hose.

When is coolant drawn back into radiator?

Coolant which has expanded as the system warms up passes down the tube into this tank, and is drawn back into the radiator when it has cooled. The system is supposed to be maintenance-free, and is drained only when a hose or the coolant is due for replacement. When draining and refilling the system, if the coolant is to be reused, ...

How to get air out of a radiator?

Top up the expansion tank if necessary when all air is out of the system. Top up the radiator. Open and close the bleed screws on the various hoses and connections in turn, ending with the heater-system screw. Close each of them as soon as there is a good flow of air-free coolant. Lower the car.

What is the best mix of antifreeze and water for car coolant?

Most manufacturers recommend a 60 to 40 per cent water and antifreeze mixture. Some specify a 50-50 mix. Use antifreeze made to BS (British Standard) 3152, or as specified by the car manufacturer.

Is coolant poisonous?

Note that the coolant is poisonous. Do not use containers which will be used in or near the kitchen. If you do not want to use the coolant again, do not pour it down a drain — ask your local council how to dispose of it.

Does a sealed cooling system need to be topped up?

The sealed cooling system. Coolant in a sealed system does not evaporate to the atmosphere, and should never need topping up. Instead, a pressure cap is fitted to the system, and a tube leads from the top of the radiator to a glass, plastic or metal tank or container. Coolant which has expanded as the system warms up passes down ...

Can you get a pressure release valve wet?

If the cap has a pressure release valve , never get it wet; replace it if it does become wet or dirty. Examine the condition of the hoses where they are held by clamps or hose clips. Reinforce them with fabric-based tape under the clamps or clips if they are wearing - or, better still, replace them.

What happens when coolant is overflowing?

As the coolant begins to cool, it contracts and increases the amount of room once again inside the cooling system. This contracting of the coolant creates a negative pressure which draws the extra coolant stored in the overflow tank back into the primary cooling system. Therefore, your overflow tank is used as an expansion vessel to allow ...

How does a radiator overflow tank work?

The radiator coolant overflow tank works by filling the tank with coolant when the cooling system’s pressure is too high and withdraw coolant from it when there is under pressure in the system .

What is a radiator pressure cap?

The radiator pressure cap is the unsung hero of your cooling system and works in unison with your overflow tank. Many people think that your radiator cap is simply a screw-on-lid for your radiator, but it’s so much more. Inside your radiator cap is a spring loaded valve. As the coolant temperature increases and the pressure inside causes ...

How does a car cool off?

Your vehicle’s cooling is simply designed to cool the engine by carrying it’s generated heat away. As your engine turns over and gets hot, the coolant that passes through and around your engine steals this heat away and carries it to the front of the car where it’s cooled off by the radiator and cooling fans.

Why does the radiator cap open?

As the coolant temperature increases and the pressure inside causes the coolant to expand, the valve inside your radiator cap opens to allow the excess coolant to flow into your overflow tank. This valve allows your cooling system to stay pressurised but will help prevent the system from over pressurising and thus overheating.

Why do we need an overflow tank?

This is the reason why we need to have an overflow tank as the pressure inside the coolant pipes increases due to the coolant solution being heated and therefore expanded. The expanded coolant needs somewhere to go. Any liquid that no longer fits inside the primary cooling system is now forced into the overflow tank, ...

What is rust protection?

Built into your vehicle’s coolant mixture is also a rust protection formula, which is designed to help prevent the internals of the cooling system from corroding and rusting from the water. What’s great about this cooling system is how adaptable it is.